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A newbie perl question

Im very new to perl, and I can't seem to figure this out:

I have a text file named data.txt that looks like this:

Code:

--BEGIN DATA--

HTTPD,1

FTP,1

SMTPD,1

OPENFIRE,1

TEST,0

--END DATA--

Im trying to figure out how I would read this file and then output to an html page in a format such as this:

Code:

HTTPD - on

FTP - on

SMTPD - on

OPENFIRE - on

TEST - off

I know how to open a file and lock it, but after that im lost.

Try this:

Code:

#!/usr/bin/perl



$FILE = '/path/to/datafile';

open(FILE, "$FILE") || die "Error: Couldn't open file $FILE";

    while (<FILE>) {

        # Ignore comments and blank lines and the begin/end data lines

        if ((!/^\s*(#|\n)/) && (!/^--/)) {

            ($name, $value) = split(',');

            chomp($value);

            print "$name - ";

            if ($value == 1) {

                print "on\n"

            } else {

                print "off\n"

            }

        }

    }

close(FILE);

HTH

Forrest

Quote:

Originally Posted by forrestt (Post 3151910)

Try this:

Code:

#!/usr/bin/perl



$FILE = '/path/to/datafile';

open(FILE, "$FILE") || die "Error: Couldn't open file $FILE";

    while (<FILE>) {

        # Ignore comments and blank lines and the begin/end data lines

        if ((!/^\s*(#|\n)/) && (!/^--/)) {

            ($name, $value) = split(',');

            chomp($value);

            print "$name - ";

            if ($value == 1) {

                print "on\n"

            } else {

                print "off\n"

            }

        }

    }

close(FILE);

HTH

Forrest

Thank you so much, that works perfectly. It looks like I've got a lot to learn.

Although it doesn't contain any file locking stuff, you can do the whole lot as a one liner:

Code:

perl -i -n -e 'if (!/^--/) { s/,1/ - on/; s/,0/ - off/; print; }' data.txt

Some explanation:

The -i means the output of the program is saved into the input file.

The -n means to execute the program for each line of the input file(s).

The -e means that the following string (enclosed in single quotes) is the program. Here it is with some formatting to help you read it:

Code:

if (!/^--/) {

    s/,1/ - on/;

    s/,0/ - off/;

    print;

}

The clause of the if says, "only do this for line which don't begin with "--".
Inside the if block are two replacements, which substitute ",1" for " - on", and ",0" for " - off". The line is then printed.

Note that none of these operations say what they are working on. This is a feature of Perl that many operations have a default argument, which is usually the $_ variable. This means "the current input line" as set by the <FILEHANDLE> operator, or in the case of your using the -n option, each line of the input file(s).

Quote:

Originally Posted by matthewg42 (Post 3151947)

Although it doesn't contain any file locking stuff, you can do the whole lot as a one liner:

Code:

perl -i -n -e 'if (!/^--/) { s/,1/ - on/; s/,0/ - off/; print; }' data.txt

Code:

if (!/^--/) {

    s/,1/ - on/;

    s/,0/ - off/;

    print;

}

Nice descriptions. Thanks.

If you haven't got it already, I highly recommend bookmarking this: http://perldoc.perl.org/
See the top left of that page for tutorials